Biosynthesis taxadienes

Jennewein, S., Long, R.M., Williams, R.M. and Croteau, R. (2004) Cytochrome P450 taxadiene 5a-hydroxy-lase, a mechanistically unusual monooxygenase catalyzing the first oxygenation step of Taxol biosynthesis. 

Huang, Q., Roessner, C.A., Croteau, R. and Scott, A.I. (2001) Engineering Escherichia coli for the synthesis of taxadiene, a key intermediate in the biosynthesis of Taxol. Bioorganic Medicinal Chemistry, 9, 2237-2242. 

By using an elegant 13C-labeling study that involved incubation of Phoma sp. with 1-13C and 1,2-13C acetate, Oikawa et al. [9], were able to isolate the proposed biosynthetic intermediate phomactatriene (or Sch 49026), with 13C incorporation from singly labeled acetate units as indicated by in Fig. 8.3. Phomactatriene is strikingly reminiscent of taxadiene, a biosynthetic intermediate for Taxol . The net biosynthesis for both involves geranylgeranyl diphosphate (GGDP) cyclization [9]. It is noteworthy that prior to isolation of phomactins, the only known related structure is cleomeolide, a diterpene from the herb Cleome viscosa [10] that remarkably resembles phomactin H. 

Besumbes O, Sauret-Giieto S, Phillips MA, Imperial S, Rodn guez-Concepcion M, Boronat A. (2004) Metabolic engineering of isoprenoid biosynthesis in Arabidopsis for the production of taxadiene, the first committed precursor of taxol. Biotechnol Bioeng 88 168-175. 

WILLIAMS, D. C., WILDUNG, M. R., JIN, A. Q. W., DALAL, D., OLIVER, J. S., COATES, R. M., CROTEAU, R., Heterologous expression and characterization of a "pseudomature" form of taxadiene synthase involved in paclitaxel (Taxol) biosynthesis and evaluation of a potential intermediate and inhibitors of the multistep diterpene cyclization reaction, Arch. Biochem. Biophys., 2000, 379, 137-146. 

The genes encoding several of the hydroxylation and acylation steps have been cloned and functionally expressed in E. coli (for a summary, see Marasco and Schmidt-Dannert, 2007). Whereas it was possible to produce the main skeleton, taxadiene, in recombinant bacteria and yeast in good yield, the later steps of taxol biosynthesis appear to be more difficult to achieve in recombinant systems at present (Jennewein et al., 2005 Dejong et al. 2006). 

Wildung, M.R. and Croteau, R. (1996) A cDNA clone for taxadiene synthase, the diterpene cyclase that catalyzes the committed step of taxol biosynthesis. /. Biol. Chem., 271, 9201-4. 

Taxadiene undergoes an extended series of oxygenation and acylation reactions to yield taxol. So far, 8 out of 20 enzymatic steps have been in vitro catalyzed through cloned cDNAs [53]. Several regioselective CoA thioester-dependent acyltransferases, including a C13-side-chain N-benzoyltransferase which predominantly forms one 3 -epimer of 2 -deoxytaxol, are involved in the synthesis. This indicates that there is still a long way to go before taxol could be produced in microorganisms from a reconstituted biosynthesis. 

Engels, B., Dahmb, P. and Jennewein, S. (2008) Metabolic engineering of taxadiene biosynthesis in yeast as a first step towards Taxol (Paclitaxel) production. Metabolic Engineering. 10, 201-206. 

Wildung MR, Croteau R (1996) A cDNA Clone for Taxadiene Synthase, the Diterpene Cyclase That Catalyzes the Committed Step of Taxol Biosynthesis. J Biol Chem 271 9201... 

Huang Q, Roessner CA, Croteau R, Scott AI (2001) Engineering Escherichia coli for the Synthesis of Taxadiene, a Key Intermediate in the Biosynthesis of Taxol. Bioorg Med Chem 9 2237... 

Utilization of the MVA pathway for IPP over the DXP pathway (Anthony et al. 2009 Morrone et al. 2010 Tsuruta et al. 2009). However, we found that the DXP pathway owns more potential for IPP supply than MVA pathway through an in silico comparison of the maximum theoretical IPP yields and thermodynamic properties between the DXP and MVA pathways with different hosts and carbon sources. Following woik on heterologous biosynthesis of TaxoFs key intermediate taxadiene via DXP pathway has confirmed our viewpoint (Meng et al. 201 lb). 

Meng HL, Wang Y, Hua Q, Zhang SL, Wang XN (2011b) In silico analysis tmd experimental improvement of taxadiene heterologous biosynthesis in Escherichia coli. Biotechnol Bioprocess Eng 16 205-215... 

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